Legislation that deals with the production of cannabis and the consumption of it and related products for either recreational or medicinal use has evolved, leading to an emergence of new regulations in terms of the impurity content, terpene profiles, and potency of such products. Among the contaminants or impurities that necessitate testing are the metals. Given their carcinogenicity and toxicity, many jurisdictions minimally require testing for mercury, cadmium, lead, and arsenic. Metals can accumulate inside plant material through what are actually quite normal metabolic processes. On top of this, a number of plants can even hyperaccumulate metals towards concentrations that are much higher than those found in the waters and soils which nourish them. Some of these metals can actually have nutritional value or other health benefits, but there are others that show various levels of outright toxicity. Given this, testing for metals, especially toxic ones, is essential for any product that is destined for eventual human consumption. A number of analytical techniques can accomplish the quantitation of any metals inside cannabis materials. Technologies amenable to this include inductively coupled plasma-mass spectrometry, inductively coupled plasma-optical emission spectroscopy, and atomic absorption spectroscopy. These three are respectively abbreviated as ICP-MS, ICP-OES, and AA. As with any kind of analytical instrumentation, every method has distinct benefits and drawbacks. We’re going to present an overview of these analytical methodologies, what challenges the analyst faces, and various notes regarding regulatory stipulations.

Recent legislative shifts inside the United States and many other countries have wound up seeing cannabis and/or related products, such as edibles, tinctures, and cannabis-based extracts being used for both recreational and medicinal purposes. In America, recent legalization efforts have mostly been emphasized at state levels, as (at the time of writing) nine states plus the District of Columbia were allowing full usage of cannabis for both recreational and medicinal purposes. At the same time, 29 states plus Puerto Rico and Guam were using cannabis for various levels of specifically medicinal uses. An additional 13 states simply decriminalized cannabis, which just means that any criminal penalties resulting from simple possession get removed. On the other hand, there remain three states that totally prohibit any use or possession of cannabis. When 2018 started, about 21 percent of all Americans lived in a state with totally legalized cannabis. Overseas, a number of nations have also various levels in regards to legality. Uruguay has gone for full legality, and the Netherlands allow partial legality, while other nations have their own decriminalization statutes which remove the criminal penalties for the use and/or possession of cannabis.

Since the final products which are destined to be consumed by humans do so through topical application, ingestion, or inhalation, jurisdictions with legal cannabis now recognize that there is need for controls over the numerous chemical aspects of both the plant as well as its derivative products. These regulations focus on things like metal content, moisture content, residual solvent content, pesticide contamination, and potency, necessitating the usage of various analytical techniques, including elemental spectroscopy methods, GC-MS, GC (gas chromatography), LC-MS (liquid chromatography-mass spectrometry), and HPLC (high-performance liquid chromatography). Such regulations are now recognized as crucially important in particular for medicinal cannabis, given how such consumers might have compromised immune responses or even weakened metabolic systems, which can limit the effectiveness their bodies have in processing or tolerating extraneous chemicals, metals, toxins, and biological materials. For the intents of this particular article, we are going to explore the nature of metal content inside cannabis and its associated materials as well as regulations surrounding them and the analytical methods used in determining them too.

The Health Effects Metals Have

Metallic elements are known for having complicated biochemistries, and their health effects within the human body are both potentially beneficial or deleterious. Even though quite a few metals serve crucial metabolic or nutritional roles inside the human body, many others can be carcinogens or toxins. For instance, when iron is consumed with food, it’s used by the human body in order to transport oxygen within the bloodstream; it’s also used for cellular respiration. On the other hand, mercury or lead consumption can cause damage to a person’s nervous system. Given the combination of both positive and negative effects, the content of any metals in products which are destined for eventual human consumption (such as food or pharmaceutical products) is often highly regulated by oversight agencies. Some such oversight agencies are local, but some are federal. Two famous examples at the federal level include the FDA or EPA, otherwise respectively known as the Food and Drug Administration or the Environmental Protection Agency.

The Presence Of Metals In Cannabis

As with any plant, cannabis will uptake metals from its surrounding environment simply as a part of its routine plant metabolic functions. Some of the associate metals occur naturally, leaching into the groundwater that a plant will uptake from the minerals and soils it grows in. Other certain metals might precipitate in rainwater as they were metal-laden atmospheric aerosols that dissolved into precipitation. Many of the atmospheric metals came up from anthropogenic sources, like refining, smelting, and a number of other industrial processes. Also, metals might even get introduced into the environment of a plant as they might be constituents of herbicides, pesticides, fertilizers, and fungicides which might be applied in order to increase crop yields. Irrespective of their individual provenance, when metals are metabolized, they get first absorbed and then secondly transported through plant roots into the broader plant tissue, and this is where they typically reside as metal complexes inside proteins and extracellular fluids.

Cannabis proves to be so effective in uptaking metals from its surrounding environment, that hemp, which is not a psychoactive variety of cannabis, is actually sometimes used as a way of bioremediating sites contaminated with metal. For instance, hemp actually saw use as a way of leaching radioactive cesium and strontium from contaminated soil in the area surrounding Chernobyl. As a matter of fact, cannabis is sometimes known as a hyperaccumulator of a variety of trace metals, including but not limited to cobalt, chromium, copper, magnesium, and lead. This actually leads to concerns that such elements might happen in high concentrations within cannabis plants which are cultivated specifically for human consumption.